With 275 million users, Dropbox is adding new features for its business users: making collaboration in existing apps easier, as well as delivering new email clients.

With over 275 million users, Dropbox CEO Drew Houston has a lot to be happy about. His company is one of the poster children of the ubiquitous computing world, providing tools for one button access to files on any device, anywhere. It's a product he describes not as cloud storage or sync, but as "freedom and peace of mind."

Certainly he thinks big, suggesting that with all those users, "everytime you can save someone fifteen minutes, you're saving 7,800 years of pain." And there's no shortage of big problems for him, as he points out. "We started with a magic folder, then we did the same for email. Now it's time for a new chapter."

In order to support a growing number of business customers, Dropbox has had to completely rebuild its infrastructure; letting it separate work and personal content. Houston says the rearchitecture is now complete, "It's all done and it works great." That rework is allowing Dropbox to launch new products and services targeted at its business users.

One area that Houston sees as ripe for change is document collaboration. While it's easy to share files in a shared folder through the service, there's the prospect of file conflicts when two users open and work on the same file.

Dropbox's Project Harmony is intended to wrap a notification and collaboration layer around existing applications, something that Houston describes as "making every piece of software collaborative." The result adds an icon much like that used on the Dropbox folders to your apps, letting you see if you have the latest version of a document.

The icon state changes when a document is opened by another author. You can see who they are, and with one click you can open up a message window without leaving your document -- and without breaking your flow. The resulting ad-hoc workflow gives you a simple way of discussing changes to a document, without having to resort to complex filenames or additional software. Once changes have been made (and saved) the icon changes again to indicate that you need to resync a document. All you need to do is click the icon and the document refreshes automatically.

Project Harmony will initially only work with Microsoft Office, across Windows and MacOS -- allowing cross platform collaboration. Houston indicated that additional apps would be added in future.

Dropbox's acquisition of Mailbox is starting to show fruit too, with Mailbox's Liz Armistead showing off two new versions: one for Android and one for the desktop.

The Android Mailbox is very similar to its iOS sibling, with the same text-forward design, and the same swipe gestures to delete, archive, list or snooze messages. Armistead noted that these tools had meant that users were working with mail on two devices, using a phone with Mailbox for triage and then replying at length on the desktop. That led to the development of a desktop version of Mailbox, initially for MacOS, shortly to enter private beta.

Like the mobile version, the desktop Mailbox is gesture driven, using the same swipes on the trackpad to handle the same tasks, with a quick compose button for replies and new messages.

Dropbox

Mailbox for Android's autoswipe automates common mail triage actions.

Armistead also announced new features for the mobile Mailbox apps, initially in Android and following in iOS, "We're adding more control to mail, but still keeping it simple." The new Autoswipe feature learns from users' swipes and creates rules that can be used to automate common actions. All you need to do is tap to accept a rule, and messages will be deleted, listed, archived, or snoozed. Preferences will synchronise through Dropbox, and users will need to sign into Mailbox with a Dropbox account.

The final launch, Carousel, was targeted at consumers, but its mix of photosharing and messaging is likely to be useful in a business context. Running on iOS and Android, Carousel provides a gallery view of your personal and shared Dropbox photo folders. Synced images appear in the Carousel gallery, sorted into events by date and location. Photos can be shared quickly, adding them to contacts' Dropboxes along with comments and messages.

It's easy to see Carousel as an alternative to complex messaging systems like MMS, with a focus purely on sharing images. It's fast, and intuitive, and easy to see how it fits into many corporate messaging scenarios - especially for realtors and other business that need to share images quickly internally and externally.

Houston describes Dropbox's vision as of a home for all your stuff, a home for your life. With today's blend of work and personal, it's positioning itself not so much as competition for the tools and servivesd that you're already using, but as a complimentary service that adds extra functionality and makes those tools more useful. It's an interesting approach, and one that makes a lot of sense as we move further and further away from one computer per desk to many devices in many places.